Techniques for determining upstream nodes in full duplex wireless communications

ABSTRACT

Aspects described herein relate to determining, by a node, to establish a first backhaul connection with a first upstream node for access link communications with a first downstream node, determining, by the node, to establish a second backhaul connection with a second upstream node for access link communications with a second downstream node, establishing the first backhaul connection with the first upstream node based on a first transmit/receive beam pair, and establishing the second backhaul connection with the second upstream node based on a second transmit/receive beam pair and while the first backhaul connection is established with the first upstream node.

CLAIM OF PRIORITY UNDER 35 U.S.C. § 119

The present Application for Patent claims priority to Provisional PatentApplication No. 62/935,427, entitled “TECHNIQUES FOR DETERMININGUPSTREAM NODES IN FULL DUPLEX WIRELESS COMMUNICATIONS” filed Nov. 14,2019, which is assigned to the assignee hereof and hereby expresslyincorporated by reference herein for all purposes.

BACKGROUND

Aspects of the present disclosure relate generally to wirelesscommunication systems, and more particularly, to determining upstreamnodes to use in full duplex wireless communications.

Wireless communication systems are widely deployed to provide varioustypes of communication content such as voice, video, packet data,messaging, broadcast, and so on. These systems may be multiple-accesssystems capable of supporting communication with multiple users bysharing the available system resources (e.g., time, frequency, andpower). Examples of such multiple-access systems include code-divisionmultiple access (CDMA) systems, time-division multiple access (TDMA)systems, frequency-division multiple access (FDMA) systems, andorthogonal frequency-division multiple access (OFDMA) systems, andsingle-carrier frequency division multiple access (SC-FDMA) systems.

These multiple access technologies have been adopted in varioustelecommunication standards to provide a common protocol that enablesdifferent wireless devices to communicate on a municipal, national,regional, and even global level. For example, a fifth generation (5G)wireless communications technology (which can be referred to as 5G newradio (5G NR)) is envisaged to expand and support diverse usagescenarios and applications with respect to current mobile networkgenerations. In an aspect, 5G communications technology can include:enhanced mobile broadband addressing human-centric use cases for accessto multimedia content, services and data; ultra-reliable low-latencycommunications (URLLC) with certain specifications for latency andreliability; and massive machine type communications, which can allow avery large number of connected devices and transmission of a relativelylow volume of non-delay-sensitive information.

In some wireless communication technologies, an access point and/orother nodes can be configured for full duplex (FD) communications wherethe access point or other nodes can concurrently transmit and receiveover wireless communication resources within the same frequency band orthe same component carrier. Access points can communicate with oneanother over one or more backhaul links; however, there can be clutterin a wireless communications path between two access points or othernodes, which can have an impact on signal-to-interference-and-noiseratio (SINR) at one or more of the access points or other nodes. Inaddition, access points can be integrated access and backhaul (IAB)nodes that can provide access link functionality to a downstream node(UE or other IAB node) and corresponding backhaul link functionalitywith an upstream node (other access point or IAB node).

SUMMARY

The following presents a simplified summary of one or more aspects inorder to provide a basic understanding of such aspects. This summary isnot an extensive overview of all contemplated aspects, and is intendedto neither identify key or critical elements of all aspects nordelineate the scope of any or all aspects. Its sole purpose is topresent some concepts of one or more aspects in a simplified form as aprelude to the more detailed description that is presented later.

According to an example, a method of wireless communication is provided.The method includes determining, by a node, to establish a firstbackhaul connection with a first upstream node for access linkcommunications with a first downstream node, determining, by the node,to establish a second backhaul connection with a second upstream nodefor access link communications with a second downstream node,establishing the first backhaul connection with the first upstream nodebased on a first transmit/receive beam pair, and establishing the secondbackhaul connection with the second upstream node based on a secondtransmit/receive beam pair and while the first backhaul connection isestablished with the first upstream node.

In a further example, an apparatus for wireless communication isprovided that includes a transceiver, a memory configured to storeinstructions, and one or more processors communicatively coupled withthe transceiver and the memory. The one or more processors areconfigured to execute the instructions to perform the operations ofmethods and examples described above and further herein. In anotheraspect, an apparatus for wireless communication is provided thatincludes means for performing the operations of methods and examplesdescribed above and further herein. In yet another aspect, acomputer-readable medium is provided including code executable by one ormore processors to perform the operations of methods and examplesdescribed above and further herein.

For example, an apparatus for wireless communication is provided thatincludes a transceiver, a memory configured to store instructions, andone or more processors communicatively coupled with the transceiver andthe memory. The one or more processors are configured to determine toestablish a first backhaul connection with a first upstream node foraccess link communications with a first downstream node, determine toestablish a second backhaul connection with a second upstream node foraccess link communications with a second downstream node, establish thefirst backhaul connection with the first upstream node based on a firsttransmit/receive beam pair, and establish the second backhaul connectionwith the second upstream node based on a second transmit/receive beampair and while the first backhaul connection is established with thefirst upstream node.

In another example, an apparatus for wireless communication is providedthat includes means for determining, by a node, to establish a firstbackhaul connection with a first upstream node for access linkcommunications with a first downstream node, means for determining, bythe node, to establish a second backhaul connection with a secondupstream node for access link communications with a second downstreamnode, means for establishing the first backhaul connection with thefirst upstream node based on a first transmit/receive beam pair, andmeans for establishing the second backhaul connection with the secondupstream node based on a second transmit/receive beam pair and while thefirst backhaul connection is established with the first upstream node.

In another example, a computer-readable medium including code executableby one or more processors to perform wireless communications isprovided. The code includes code for determining, by a node, toestablish a first backhaul connection with a first upstream node foraccess link communications with a first downstream node, determining, bythe node, to establish a second backhaul connection with a secondupstream node for access link communications with a second downstreamnode, establishing the first backhaul connection with the first upstreamnode based on a first transmit/receive beam pair, and establishing thesecond backhaul connection with the second upstream node based on asecond transmit/receive beam pair and while the first backhaulconnection is established with the first upstream node.

To the accomplishment of the foregoing and related ends, the one or moreaspects comprise the features hereinafter fully described andparticularly pointed out in the claims. The following description andthe annexed drawings set forth in detail certain illustrative featuresof the one or more aspects. These features are indicative, however, ofbut a few of the various ways in which the principles of various aspectsmay be employed, and this description is intended to include all suchaspects and their equivalents.

BRIEF DESCRIPTION OF THE DRAWINGS

The disclosed aspects will hereinafter be described in conjunction withthe appended drawings, provided to illustrate and not to limit thedisclosed aspects, wherein like designations denote like elements, andin which:

FIG. 1 illustrates an example of a wireless communication system, inaccordance with various aspects of the present disclosure;

FIG. 2 is a block diagram illustrating an example of a base station, inaccordance with various aspects of the present disclosure;

FIG. 3 is a flow chart illustrating an example of a method fordetermining upstream nodes and/or transmit/receive beam pairs, inaccordance with various aspects of the present disclosure;

FIG. 4 illustrates an example of a node for determining upstream nodesand/or transmit/receive beams in the presence of clutter, in accordancewith various aspects of the present disclosure; and

FIG. 5 is a block diagram illustrating an example of a MIMOcommunication system including base stations in backhaul communications,in accordance with various aspects of the present disclosure.

DETAILED DESCRIPTION

Various aspects are now described with reference to the drawings. In thefollowing description, for purposes of explanation, numerous specificdetails are set forth in order to provide a thorough understanding ofone or more aspects. It may be evident, however, that such aspect(s) maybe practiced without these specific details.

The described features generally relate to determining upstream nodes touse in providing uplink and downlink communication functionality usingfull duplex (FD) wireless communications. For example, a node canoperate to utilize downlink and uplink wireless communications, and maydo so concurrently by virtue of FD wireless communications. In addition,in one example, the node can concurrently communicate with differentnodes using the downlink and uplink communications. In an example, FDcommunications at a node can be impacted by clutter caused by objectsinterfering with wireless signals. For example, an object can cause atransmitted signal to be reflected back to an access point, and in FDcommunications, the reflected signal can be received and can interferewith other received wireless communications. Said differently, a receivepath of a node in FD communications may experience self-interferencefrom clutter that the transmit path may not see (e.g., where the cluttercauses the transmitted signal to at least partially reflect to thereceiver of the node).

FD communications, as referred to herein, can include a single node(e.g., an access point) transmitting and receiving (e.g., concurrently)over communication resources in the same frequency band and/or overcommunication resources in the same component carrier (CC). In oneexample, FD communications can include in-band full duplex (IBFD) wherethe single node can transmit and receive on the same time and frequencyresource, and the downlink and uplink can share the same IBFDtime/frequency resources (e.g., full and/or partial overlap). In anotherexample, FD communications can include sub-band FD (also referred to as“flexible duplex”) where the single node can transmit and receive at thesame time but on different frequency resources within the same frequencyband (or over communication resources in the same CC), where thedownlink resource and the uplink resources can be separated in thefrequency domain (e.g., by a guard band). For example, the guard band insub-band FD can be on the order of resource block (RB) widths (e.g., 180kilohertz (kHz) for third generation partnership project (3GPP) longterm evolution (LTE) and fifth generation (5G) new radio (NR), 60 and120 kHz for NR, etc.). This can be distinguished from a guard band infrequency division duplexing (FDD) communications defined in LTE and NR,which can be 5 megahertz (MHz) or more, and the associated resources inFDD are defined between frequency bands, but not within the samefrequency band (or resources in the same CC) as is the case in sub-bandFD communications.

FD systems can have increased rate and spectral efficiency overhalf-duplex systems as simultaneous transmit/receive are possible. Inaddition, enhanced self-interference (and thus decreasedsignal-to-interference-and-noise ratio (SINR)) from the transmit part ofthe system on the receive part of the system is possible due to impactof clutter, as described herein. In some examples of FD communications,various antenna configurations can be used within a device (e.g., anaccess point) to facilitate FD communications. In one configuration, atransmit antenna array can be spatially separated or isolated from areceive antenna array within the device to reduce leakage (e.g.,self-interference) from the transmit antenna array into the receiveantenna array. The circuitry used to achieve this isolation may be moreamenable for backhaul or customer premises equipment (CPE)-typeapplications. In another example, the antenna array configuration ofnon-FD communications can use the same antenna array(s) for transmittingor receiving (but not both).

In addition, in an example, a node can communicate with one or moreupstream devices and/or one or more different downstream devices. Inthis example, a node can serve a device (e.g., a user equipment (UE) orother downstream node, such as an integrated access and backhaul (IAB)node) on an access link and can connect with one or more upstream nodes(also referred to as backhaul nodes) over a backhaul link. For a givennode, as the upstream and/or downstream node(s) to which the given nodeconnects can be in different locations, there may be asymmetry in termsof local clutter experienced at any given node. For example, clutter mayinclude any object that can act as a reflector, diffractor, scatterer,etc. that redirects signal energy, such as a building, tree, car, etc.In addition, clutter can be static or dynamic and the associated objectmay be mobile (e.g., moving) or time-varying in terms of induced gains.Clutter around a given node can be dense or sparse and can be dependenton local geometry and/or channel environment.

Additionally, for example, in serving different downstream nodes, beamsused to direct signal energy toward a given downstream node on an accesslink and/or to a given upstream node on a backhaul link may haveasymmetry with other beams used to direct signal energy to otherdownstream and/or upstream devices due to clutter in the given signaldirection(s). Thus, for example, for a given node, communicationsrelated to different downstream nodes may traverse different paths thatmay include different upstream nodes. For example, a given node mayconnect to different parent upstream nodes (i.e., backhaul nodes) fordownlink and uplink communications to achieve a desirable signalquality, throughput, etc. even when clutter is present.

In another example, a given node can establish beam pairs forcommunicating with another node, which may include a transmit beam and areceive beam. Generally, a node can create a transmit beam bybeamforming antenna resources to transmit a signal in a beamformeddirection by directing signal energy of the antenna resources such toachieve a signal transmitted in the beamformed direction. Similarly, anode can create a receive beam by beamforming antenna resources toreceive a signal from a beamformed direction by directing the antennaresources to receive a signal in the beamformed direction. Atransmit/receive beam pair for a given link can generally be similar totransmit signals to and receive signals from a given device. Whereclutter exists, however, transmitting in one direction may at leastcause some self-interference at a receiver of the transmitting node inFD communications. Thus, the transmit/receive beams in a beam pair maybe different to avoid such self-interference.

Aspects described herein relate to determining upstream nodes to be usedto serve different downstream nodes using FD communications whereclutter may be present. For example, a given node, such as an IAB node,serving multiple downstream devices may determine to use differentupstream devices to serve at least two different downstream devices. Inan example, the given node may determine one upstream node to bedesirable for serving a downstream node (e.g., based on measuringproperties of signals received from the upstream node), but maydetermine the upstream node is not desirable for serving a differentdownstream node (e.g., due to self-interference caused in receivingsignals from the upstream node while transmitting signals to thedifferent downstream node). In this example, the given node may select adifferent upstream node to use in serving the different downstream node.

In an example, nodes, as referred to herein, can include substantiallyany type of node capable of FD wireless communications, which mayinclude any class of device defined in third generation partnershipproject (3GPP), such as a UE, a IAB node, customer premises equipment(CPE), base station or other access point, relay node, repeater (e.g.,smart or dumb repeater), etc., which can communicate over an accesslink, sidelink, etc., as described further herein.

The described features will be presented in more detail below withreference to FIGS. 1-5.

As used in this application, the terms “component,” “module,” “system”and the like are intended to include a computer-related entity, such asbut not limited to hardware, software, a combination of hardware andsoftware, or software in execution. For example, a component may be, butis not limited to being, a process running on a processor, a processor,an object, an executable, a thread of execution, a program, and/or acomputer. By way of illustration, both an application running on acomputing device and the computing device can be a component. One ormore components can reside within a process and/or thread of executionand a component can be localized on one computer and/or distributedbetween two or more computers. In addition, these components can executefrom various computer readable media having various data structuresstored thereon. The components can communicate by way of local and/orremote processes such as in accordance with a signal having one or moredata packets, such as data from one component interacting with anothercomponent in a local system, distributed system, and/or across a networksuch as the Internet with other systems by way of the signal. Softwareshall be construed broadly to mean instructions, instruction sets, code,code segments, program code, programs, subprograms, software modules,applications, software applications, software packages, routines,subroutines, objects, executables, threads of execution, procedures,functions, etc., whether referred to as software, firmware, middleware,microcode, hardware description language, or otherwise.

Techniques described herein may be used for various wirelesscommunication systems such as CDMA, TDMA, FDMA, OFDMA, SC-FDMA, andother systems. The terms “system” and “network” may often be usedinterchangeably. A CDMA system may implement a radio technology such asCDMA2000, Universal Terrestrial Radio Access (UTRA), etc. CDMA2000covers IS-2000, IS-95, and IS-856 standards. IS-2000 Releases 0 and Aare commonly referred to as CDMA2000 1×, 1×, etc. IS-856 (TIA-856) iscommonly referred to as CDMA2000 1×EV-DO, High Rate Packet Data (HRPD),etc. UTRA includes Wideband CDMA (WCDMA) and other variants of CDMA. ATDMA system may implement a radio technology such as Global System forMobile Communications (GSM). An OFDMA system may implement a radiotechnology such as Ultra Mobile Broadband (UMB), Evolved UTRA (E-UTRA),Institute of Electrical and Electronic Engineers (IEEE) 802.11 (Wi-Fi),IEEE 802.16 (WiMAX), IEEE 802.20, Flash-OFDM™, etc. UTRA and E-UTRA arepart of Universal Mobile Telecommunication System (UMTS). 3GPP Long TermEvolution (LTE) and LTE-Advanced (LTE-A) are new releases of UMTS thatuse E-UTRA. UTRA, E-UTRA, UMTS, LTE, LTE-A, and GSM are described indocuments from an organization named “3rd Generation PartnershipProject” (3GPP). CDMA2000 and UMB are described in documents from anorganization named “3rd Generation Partnership Project 2” (3GPP2). Thetechniques described herein may be used for the systems and radiotechnologies mentioned above as well as other systems and radiotechnologies, including cellular (e.g., LTE) communications over ashared radio frequency spectrum band. The description below, however,describes an LTE/LTE-A system for purposes of example, and LTEterminology is used in much of the description below, although thetechniques are applicable beyond LTE/LTE-A applications (e.g., to fifthgeneration (5G) new radio (NR) networks or other next generationcommunication systems).

The following description provides examples, and is not limiting of thescope, applicability, or examples set forth in the claims. Changes maybe made in the function and arrangement of elements discussed withoutdeparting from the scope of the disclosure. Various examples may omit,substitute, or add various procedures or components as appropriate. Forinstance, the methods described may be performed in an order differentfrom that described, and various steps may be added, omitted, orcombined. Also, features described with respect to some examples may becombined in other examples.

Various aspects or features will be presented in terms of systems thatcan include a number of devices, components, modules, and the like. Itis to be understood and appreciated that the various systems can includeadditional devices, components, modules, etc. and/or may not include allof the devices, components, modules etc. discussed in connection withthe figures. A combination of these approaches can also be used.

FIG. 1 is a diagram illustrating an example of a wireless communicationssystem and an access network 100. The wireless communications system(also referred to as a wireless wide area network (WWAN)) can includebase stations 102, UEs 104, an Evolved Packet Core (EPC) 160, and/or a5G Core (5GC) 190. The base stations 102 may include macro cells (highpower cellular base station) and/or small cells (low power cellular basestation). The macro cells can include base stations. The small cells caninclude femtocells, picocells, and microcells. In an example, the basestations 102 may also include gNBs 180, as described further herein. Inone example, some nodes of the wireless communication system may have amodem 240 and backhaul component 242 for communicating with one anotherover a wireless or wired backhaul link 134, as described herein. Thougha base station 102 is shown as having the modem 240 and backhaulcomponent 242, this is one illustrative example, and substantially anynode or type of node may include a modem 240 and backhaul component forproviding corresponding functionalities described herein.

The base stations 102 configured for 4G LTE (which can collectively bereferred to as Evolved Universal Mobile Telecommunications System (UMTS)Terrestrial Radio Access Network (E-UTRAN)) may interface with the EPC160 through backhaul links 132 (e.g., using an S1 interface). The basestations 102 configured for 5G NR (which can collectively be referred toas Next Generation RAN (NG-RAN)) may interface with 5GC 190 throughbackhaul links 184. In addition to other functions, the base stations102 may perform one or more of the following functions: transfer of userdata, radio channel ciphering and deciphering, integrity protection,header compression, mobility control functions (e.g., handover, dualconnectivity), inter-cell interference coordination, connection setupand release, load balancing, distribution for non-access stratum (NAS)messages, NAS node selection, synchronization, radio access network(RAN) sharing, multimedia broadcast multicast service (MBMS), subscriberand equipment trace, RAN information management (RIM), paging,positioning, and delivery of warning messages. The base stations 102 maycommunicate directly or indirectly (e.g., through the EPC 160 or 5GC190) with each other over backhaul links 134 (e.g., using an X2interface). The backhaul links 134 may be wired or wireless.

The base stations 102 may wirelessly communicate with one or more UEs104. Each of the base stations 102 may provide communication coveragefor a respective geographic coverage area 110. There may be overlappinggeographic coverage areas 110. For example, the small cell 102′ may havea coverage area 110′ that overlaps the coverage area 110 of one or moremacro base stations 102. A network that includes both small cell andmacro cells may be referred to as a heterogeneous network. Aheterogeneous network may also include Home Evolved Node Bs (eNBs)(HeNBs), which may provide service to a restricted group, which can bereferred to as a closed subscriber group (CSG). The communication links120 between the base stations 102 and the UEs 104 may include uplink(UL) (also referred to as reverse link) transmissions from a UE 104 to abase station 102 and/or downlink (DL) (also referred to as forward link)transmissions from a base station 102 to a UE 104. The communicationlinks 120 may use multiple-input and multiple-output (MIMO) antennatechnology, including spatial multiplexing, beamforming, and/or transmitdiversity. The communication links may be through one or more carriers.The base stations 102/UEs 104 may use spectrum up to Y MHz (e.g., 5, 10,15, 20, 100, 400, etc. MHz) bandwidth per carrier allocated in a carrieraggregation of up to a total of Yx MHz (e.g., for x component carriers)used for transmission in the DL and/or the UL direction. The carriersmay or may not be adjacent to each other. Allocation of carriers may beasymmetric with respect to DL and UL (e.g., more or less carriers may beallocated for DL than for UL). The component carriers may include aprimary component carrier and one or more secondary component carriers.A primary component carrier may be referred to as a primary cell (PCell)and a secondary component carrier may be referred to as a secondary cell(SCell).

In another example, certain UEs 104 may communicate with each otherusing device-to-device (D2D) communication link 158. The D2Dcommunication link 158 may use the DL/UL WWAN spectrum. The D2Dcommunication link 158 may use one or more sidelink channels, such as aphysical sidelink broadcast channel (PSBCH), a physical sidelinkdiscovery channel (PSDCH), a physical sidelink shared channel (PSSCH),and a physical sidelink control channel (PSCCH). D2D communication maybe through a variety of wireless D2D communications systems, such as forexample, FlashLinQ, WiMedia, Bluetooth, ZigBee, Wi-Fi based on the IEEE802.11 standard, LTE, or NR.

The wireless communications system may further include a Wi-Fi accesspoint (AP) 150 in communication with Wi-Fi stations (STAs) 152 viacommunication links 154 in a 5 GHz unlicensed frequency spectrum. Whencommunicating in an unlicensed frequency spectrum, the STAs 152/AP 150may perform a clear channel assessment (CCA) prior to communicating inorder to determine whether the channel is available.

The small cell 102′ may operate in a licensed and/or an unlicensedfrequency spectrum. When operating in an unlicensed frequency spectrum,the small cell 102′ may employ NR and use the same 5 GHz unlicensedfrequency spectrum as used by the Wi-Fi AP 150. The small cell 102′,employing NR in an unlicensed frequency spectrum, may boost coverage toand/or increase capacity of the access network.

A base station 102, whether a small cell 102′ or a large cell (e.g.,macro base station), may include an eNB, gNodeB (gNB), or other type ofbase station. Some base stations, such as gNB 180 may operate in atraditional sub 6 GHz spectrum, in millimeter wave (mmW) frequencies,and/or near mmW frequencies in communication with the UE 104. When thegNB 180 operates in mmW or near mmW frequencies, the gNB 180 may bereferred to as an mmW base station. Extremely high frequency (EHF) ispart of the RF in the electromagnetic spectrum. EHF has a range of 30GHz to 300 GHz and a wavelength between 1 millimeter and 10 millimeters.Radio waves in the band may be referred to as a millimeter wave. NearmmW may extend down to a frequency of 3 GHz with a wavelength of 100millimeters. The super high frequency (SHF) band extends between 3 GHzand 30 GHz, also referred to as centimeter wave. Communications usingthe mmW/near mmW radio frequency band has extremely high path loss and ashort range. The mmW base station 180 may utilize beamforming 182 withthe UE 104, and/or for backhaul links with other base stations asdescribed herein, to compensate for the extremely high path loss andshort range. A base station 102 referred to herein can include a gNB180.

The EPC 160 may include a Mobility Management Entity (MME) 162, otherMMES 164, a Serving Gateway 166, a Multimedia Broadcast MulticastService (MBMS) Gateway 168, a Broadcast Multicast Service Center (BM-SC)170, and a Packet Data Network (PDN) Gateway 172. The MME 162 may be incommunication with a Home Subscriber Server (HSS) 174. The MME 162 isthe control node that processes the signaling between the UEs 104 andthe EPC 160. Generally, the MME 162 provides bearer and connectionmanagement. All user Internet protocol (IP) packets are transferredthrough the Serving Gateway 166, which itself is connected to the PDNGateway 172. The PDN Gateway 172 provides UE IP address allocation aswell as other functions. The PDN Gateway 172 and the BM-SC 170 areconnected to the IP Services 176. The IP Services 176 may include theInternet, an intranet, an IP Multimedia Subsystem (IMS), a PacketSwitched (PS) Streaming Service, and/or other IP services. The BM-SC 170may provide functions for MBMS user service provisioning and delivery.The BM-SC 170 may serve as an entry point for content provider MBMStransmission, may be used to authorize and initiate MBMS Bearer Serviceswithin a public land mobile network (PLMN), and may be used to scheduleMBMS transmissions. The MBMS Gateway 168 may be used to distribute MBMStraffic to the base stations 102 belonging to a Multicast BroadcastSingle Frequency Network (MBSFN) area broadcasting a particular service,and may be responsible for session management (start/stop) and forcollecting eMBMS related charging information.

The 5GC 190 may include an Access and Mobility Management Function (AMF)192, other AMFs 193, a Session Management Function (SMF) 194, and a UserPlane Function (UPF) 195. The AMF 192 may be in communication with aUnified Data Management (UDM) 196. The AMF 192 can be a control nodethat processes the signaling between the UEs 104 and the 5GC 190.Generally, the AMF 192 can provide QoS flow and session management. UserInternet protocol (IP) packets (e.g., from one or more UEs 104) can betransferred through the UPF 195. The UPF 195 can provide UE IP addressallocation for one or more UEs, as well as other functions. The UPF 195is connected to the IP Services 197. The IP Services 197 may include theInternet, an intranet, an IP Multimedia Subsystem (IMS), a PS StreamingService, and/or other IP services.

The base station may also be referred to as a gNB, Node B, evolved NodeB (eNB), an access point, a base transceiver station, a radio basestation, a radio transceiver, a transceiver function, a basic serviceset (BSS), an extended service set (ESS), a transmit reception point(TRP), or some other suitable terminology. The base station 102 providesan access point to the EPC 160 or 5GC 190 for a UE 104. Examples of UEs104 include a cellular phone, a smart phone, a session initiationprotocol (SIP) phone, a laptop, a personal digital assistant (PDA), asatellite radio, a positioning system (e.g., satellite, terrestrial), amultimedia device, a video device, a digital audio player (e.g., MP3player), a camera, a game console, a tablet, a smart device, robots,drones, an industrial/manufacturing device, a wearable device (e.g., asmart watch, smart clothing, smart glasses, virtual reality goggles, asmart wristband, smart jewelry (e.g., a smart ring, a smart bracelet)),a vehicle/a vehicular device, a meter (e.g., parking meter, electricmeter, gas meter, water meter, flow meter), a gas pump, a large or smallkitchen appliance, a medical/healthcare device, an implant, asensor/actuator, a display, or any other similar functioning device.Some of the UEs 104 may be referred to as IoT devices (e.g., meters,pumps, monitors, cameras, industrial/manufacturing devices, appliances,vehicles, robots, drones, etc.). IoT UEs may include machine typecommunication (MTC)/enhanced MTC (eMTC, also referred to as category(CAT)-M or Cat M1) UEs, NB-IoT (also referred to as CAT NB1) UEs, aswell as other types of UEs. In the present disclosure, eMTC and NB-IoTmay refer to future technologies that may evolve from or may be based onthese technologies. For example, eMTC may include FeMTC (further eMTC),eFeMTC (enhanced further eMTC), mMTC (massive MTC), etc., and NB-IoT mayinclude eNB-IoT (enhanced NB-IoT), FeNB-IoT (further enhanced NB-IoT),etc. The UE 104 may also be referred to as a station, a mobile station,a subscriber station, a mobile unit, a subscriber unit, a wireless unit,a remote unit, a mobile device, a wireless device, a wirelesscommunications device, a remote device, a mobile subscriber station, anaccess terminal, a mobile terminal, a wireless terminal, a remoteterminal, a handset, a user agent, a mobile client, a client, or someother suitable terminology.

In an example, backhaul component 242 can be configured to performbackhaul communications with one or more base stations 102/gNBs 180using FD. In an example, backhaul component 242 can determine one ormore beams to use for the backhaul communications, which can include oneor more transmit/receive beam pairs per backhaul connection 134. In anexample, a base station 102/gNB 180 can communicate with multiple otherbase stations 102/gNBs 180 over different backhaul connections 134, andcan accordingly determine a transmit/receive beam pair for each backhaulconnection 134. For example, a base station 102/gNB 180 can perform beamtraining with one or more other base stations 102/gNBs 180, orself-training, to determine one or more beams (or one or moretransmit/receive beam pairs) to use in communicating with the one ormore other base stations 102/gNBs 180, as described further herein.

In one example, a base station 102/gNB 180 can be a JAB node that cancommunicate with one or more upstream JAB nodes (e.g., other basestation(s) 102/gNB(s) 180) over a backhaul connection 134 and one ormore downstream JAB nodes (e.g., UE(s) 104 or other base station(s)102/gNB(s) 180) over an access link (e.g., communication link 120). Inthis example, for a given downstream node, the base station 102/gNB 180IAB node, e.g., via backhaul component 242, can establish a firstconnection with one upstream node for receiving downlink communicationsto transmit to the downstream node and can establish a second connectionwith the same or a different upstream node for transmitting uplinkcommunications from the downstream node. In addition, for example, thebase station 102/gNB 180 JAB, e.g., via backhaul component 242, node canestablish a first connection with one upstream node for receivingdownlink communications to transmit to the downstream node and/or fortransmitting uplink communications from the downstream node, and canestablish a second connection with a different upstream node forreceiving downlink communications to transmit to a different downstreamnode and/or for transmitting uplink communications from the differentdownstream node.

Turning now to FIGS. 2-5, aspects are depicted with reference to one ormore components and one or more methods that may perform the actions oroperations described herein, where aspects in dashed line may beoptional. Although the operations described below in FIG. 3 arepresented in a particular order and/or as being performed by an examplecomponent, it should be understood that the ordering of the actions andthe components performing the actions may be varied, depending on theimplementation. Moreover, it should be understood that the followingactions, functions, and/or described components may be performed by aspecially programmed processor, a processor executingspecially-programmed software or computer-readable media, or by anyother combination of a hardware component and/or a software componentcapable of performing the described actions or functions.

Referring to FIG. 2, one example of an implementation of a base station102 (and/or gNB 180) may include a variety of components, some of whichhave already been described above and are described further herein,including components such as one or more processors 212 and memory 216and transceiver 202 in communication via one or more buses 244, whichmay operate in conjunction with modem 240 and/or backhaul component 242for communicating with one or more other base stations 102/gNBs 180 overa backhaul connection 134, determining beams for FD backhaulcommunications, etc., as described herein, and/or for communicating withone or more other nodes, such as components of the core network (e.g.,EPC 160 or 5GC 190, etc.). Base station 102 may also optionally includean access link component 246 for communicating with one or more UEs 104over an access link (e.g., to provide IAB node functionality).

In an aspect, the one or more processors 212 can include a modem 240and/or can be part of the modem 240 that uses one or more modemprocessors. Thus, the various functions related to backhaul component242 may be included in modem 240 and/or processors 212 and, in anaspect, can be executed by a single processor, while in other aspects,different ones of the functions may be executed by a combination of twoor more different processors. For example, in an aspect, the one or moreprocessors 212 may include any one or any combination of a modemprocessor, or a baseband processor, or a digital signal processor, or atransmit processor, or a receiver processor, or a transceiver processorassociated with transceiver 202. In other aspects, some of the featuresof the one or more processors 212 and/or modem 240 associated withbackhaul component 242 may be performed by transceiver 202.

Also, memory 216 may be configured to store data used herein and/orlocal versions of applications 275 or backhaul component 242 and/or oneor more of its subcomponents being executed by at least one processor212. Memory 216 can include any type of computer-readable medium usableby a computer or at least one processor 212, such as random accessmemory (RAM), read only memory (ROM), tapes, magnetic discs, opticaldiscs, volatile memory, non-volatile memory, and any combinationthereof. In an aspect, for example, memory 216 may be a non-transitorycomputer-readable storage medium that stores one or morecomputer-executable codes defining backhaul component 242 and/or one ormore of its subcomponents, and/or data associated therewith, when basestation 102 is operating at least one processor 212 to execute backhaulcomponent 242 and/or one or more of its subcomponents.

Transceiver 202 may include at least one receiver 206 and at least onetransmitter 208. Receiver 206 may include hardware and/or softwareexecutable by a processor for receiving data, the code comprisinginstructions and being stored in a memory (e.g., computer-readablemedium). Receiver 206 may be, for example, a radio frequency (RF)receiver. In an aspect, receiver 206 may receive signals transmitted byat least one base station 102. Additionally, receiver 206 may processsuch received signals, and also may obtain measurements of the signals,such as, but not limited to, Ec/Io, signal-to-noise ratio (SNR),reference signal received power (RSRP), received signal strengthindicator (RSSI), etc. Transmitter 208 may include hardware and/orsoftware executable by a processor for transmitting data, the codecomprising instructions and being stored in a memory (e.g.,computer-readable medium). A suitable example of transmitter 208 mayincluding, but is not limited to, an RF transmitter.

Moreover, in an aspect, base station 102 may include RF front end 288,which may operate in communication with one or more antennas 265 andtransceiver 202 for receiving and transmitting radio transmissions, forexample, wireless communications transmitted by another base station orwireless transmissions transmitted by base station 102. RF front end 288may be connected to one or more antennas 265 and can include one or morelow-noise amplifiers (LNAs) 290, one or more switches 292, one or morepower amplifiers (PAs) 298, and one or more filters 296 for transmittingand receiving RF signals.

In an aspect, LNA 290 can amplify a received signal at a desired outputlevel. In an aspect, each LNA 290 may have a specified minimum andmaximum gain values. In an aspect, RF front end 288 may use one or moreswitches 292 to select a particular LNA 290 and its specified gain valuebased on a desired gain value for a particular application.

Further, for example, one or more PA(s) 298 may be used by RF front end288 to amplify a signal for an RF output at a desired output powerlevel. In an aspect, each PA 298 may have specified minimum and maximumgain values. In an aspect, RF front end 288 may use one or more switches292 to select a particular PA 298 and its specified gain value based ona desired gain value for a particular application.

Also, for example, one or more filters 296 can be used by RF front end288 to filter a received signal to obtain an input RF signal. Similarly,in an aspect, for example, a respective filter 296 can be used to filteran output from a respective PA 298 to produce an output signal fortransmission. In an aspect, each filter 296 can be connected to aspecific (e.g., specific to that filter 296) LNA 290 and/or PA 298. Inan aspect, RF front end 288 can use one or more switches 292 to select atransmit or receive path using a specified filter 296, LNA 290, and/orPA 298, based on a configuration as specified by transceiver 202 and/orprocessor 212.

As such, transceiver 202 may be configured to transmit and receivewireless signals through one or more antennas 265 via RF front end 288.In an aspect, transceiver may be tuned to operate at specifiedfrequencies such that base station 102 can communicate with, forexample, one or more other base stations over a backhaul connection(and/or with one or more UEs over an access link). In an aspect, forexample, modem 240 can configure transceiver 202 to operate at aspecified frequency and power level based on the configuration of thebase station 102 and the communication protocol used by modem 240.

In an aspect, modem 240 can be a multiband-multimode modem, which canprocess digital data and communicate with transceiver 202 such that thedigital data is sent and received using transceiver 202. In an aspect,modem 240 can be multiband and be configured to support multiplefrequency bands for a given communications protocol. In an aspect, modem240 can be multimode and be configured to support multiple operatingnetworks and communications protocols. In an aspect, modem 240 cancontrol one or more components of base station 102 (e.g., RF front end288, transceiver 202) to enable transmission and/or reception of signalsfrom the network based on a specified modem configuration. In an aspect,the modem configuration can be based on the mode of the modem and thefrequency band in use. In another aspect, the modem configuration can bebased on configuration information associated with base station 102 asprovided by the network or other components.

In an aspect, backhaul component 242 can optionally include abeamforming component 252 for generating transmit beams for transmittingcommunications over a backhaul connection and/or generating receivebeams for receiving communications over the backhaul connection, aconfiguration processing component 254 for receiving and/or processing aconfiguration received from a centralized entity that indicatestransmit/receive beam pairs and/or corresponding upstream nodes withwhich to establish a connection for backhaul communications, and/or abeam determining component 256 for determining one or more upstreamnodes, a transmit beam, receive beam, and/or transmit/receive beam pairto use for FD communications over a backhaul connection, as describedherein.

In an aspect, the processor(s) 212 may correspond to one or more of theprocessors described in connection with the base station(s) in FIG. 5.Similarly, the memory 216 may correspond to the memory described inconnection with the base station(s) in FIG. 5.

FIG. 3 illustrates a flow chart of an example of a method 300 fordetermining nodes with which to establish a connection for backhaulcommunications and/or transmit and/or receive beam pairs to use for FDbackhaul communications with the nodes. In an example, a base station102 can perform the functions described in method 300 using one or moreof the components described in FIGS. 1 and 2.

In method 300, optionally at Block 302, access link connections can beestablished with one or more downstream nodes. In an aspect, access linkcomponent 246, e.g., in conjunction with processor(s) 212, memory 216,transceiver 202, etc., can establish the access link connections withthe one or more downstream nodes. In one example, as described, basestation 102 can be an IAB node capable of communicating with upstreamnodes and downstream nodes such to facilitate connection between theupstream nodes and downstream nodes. For example, base station 102 canestablish backhaul links with upstream nodes (e.g., other base stations102) and access links with downstream nodes (e.g., UEs 104 and/or otherbase station 102 IAB nodes). In this example, base station 102 canforward, over an access link, communications received from an upstreamnode, on the backhaul link, to a downstream node and can forward, overthe backhaul link, communications received from the downstream node, onthe access link, to the upstream node. As described further herein, basestation 102 can forward communications received from different upstreamnodes intended for different downstream nodes to the differentdownstream nodes and/or can forward uplink communications received fromdifferent downstream nodes to different upstream nodes.

In an example, access link component 246 can establish the access linkconnections with the downstream nodes based on requests from thedownstream nodes (e.g., requests from UEs 104, requests from UEs 104forwarded from one or more downstream IAB nodes, etc.). In one example,as described further herein, base station 102 can determine to establishconnections with different upstream nodes for receiving downlinkcommunications for the downstream node and for transmitting uplinkcommunications from the downstream node to mitigate interference orself-interference that may be caused by clutter. In addition, forexample, access link component 246 can establish the access linkconnections using an access node function or functionality (AN-F) of theIAB node, which can establish an access link connection using similarfunctions as a base station 102 (e.g., gNB, etc., providing signalingand/or resources for allowing the one or more downstream nodes to randomaccess procedure, etc.). For example, the functions for establishing theaccess link connection can be defined in a radio access technology (RAT)used by the IAB node and/or base stations 102 for communicating with oneor more base stations 102, such as 5G NR for gNB.

In method 300, at Block 304, it can be determined to establish a firstbackhaul connection with a first upstream node for access linkcommunications with a first downstream node. In an aspect, beamdetermining component 256, e.g., in conjunction with processor(s) 212,memory 216, transceiver 202, backhaul component 242, etc., can determineto establish the first backhaul connection with the first upstream nodefor access link communications with the first downstream node. Forexample, beam determining component 256 can determine to establish thefirst backhaul connection based at least in part on establishing anaccess link connection with the first downstream node. In this example,beam determining component 256 can determine the first upstream node touse for receiving downlink communications intended for the firstdownstream node (or one or more other downstream nodes connected to thefirst downstream node).

In one example, beam determining component 256 can determine toestablish the first backhaul connection with the first upstream nodebased on a signal quality, strength, (e.g., signal-to-noise ratio (SNR),signal-to-interference-and-noise ratio (SINR), received signal strengthindicator (RSSI), reference signal received power (RSRP), referencesignal received quality (RSRQ), etc.) or other property of signalsreceived from the first upstream node. For example, beam determiningcomponent 256 can measure signals received from various upstream nodesand can compare the signals to determine the first upstream node withwhich to establish the first backhaul connection. This may includecomparing beams received from the various upstream nodes, as describedfurther herein.

For example, in method 300, optionally at Block 306, beam training canbe performed. In an aspect, beam determining component 256, e.g., inconjunction with processor(s) 212, memory 216, transceiver 202, backhaulcomponent 242, etc., can perform beam training with various upstreamnodes to determine transmit/receive beam pairs used to communicate withone or more of the various upstream nodes. For example, in beamtraining, for a number of nodes (e.g., base stations 102 and/or UEs 104)that are capable of FD backhaul communications (referred to as “FDnodes” or “nodes” herein) in the network, let the transmit part of eachFD node use N beams and let the receive part of each FD node use Mbeams. In this example, beam determining component 256 can perform abeam training operation from each transmit part sequentially bytransmitting each of the N beams while all receive parts (including thereceive part of the base station 102 transmitting and other nodes)receive the beams using each of the M receive beams. This process can berepeated by transmit parts for each FD node until all FD nodes havetransmitted beams, which were received by all receive parts of the otherFD nodes (and the receive parts of the transmitting FD node itself).

In this example, in determining to establish the first backhaulconnection at Block 304, optionally at Block 308, the first upstreamnode and/or a first transmit/receive beam pair can be determined basedon the beam training. In an aspect, beam determining component 256,e.g., in conjunction with processor(s) 212, memory 216, transceiver 202,backhaul component 242, etc., can determine the first upstream nodeand/or the first transmit/receive beam pair based on the beam training.As described, for example, this may include beam determining component256 first determining to establish the first connection with the firstupstream node based at least in part on signal properties of signalsreceived from the first upstream node. In addition, this can includebeam determining component 256 determining the first transmit/receivebeam pair to use with the first upstream node based on an indication ofa beam pair received from the first upstream node, determining desirablebeam pairs that are not subject to self-interference from clutter (e.g.,based on SINR, SNR, or other signal measurements, which can bedetermined as part of beam training, etc.) and selecting or otherwiserequesting to use such beam pairs, etc.

In one example, beam determining component 256 can determine the secondupstream node based on determining that, for a different upstream node,access link communications with the second downstream node causeself-interference to backhaul link communications from the differentupstream node. For example, beam determining component 256 can discoverthe self-interference during beam training, such as based on determininga beam configured to be used in the access link communications (e.g., atransmit beam or receive beam) causes self-interference to one or morebeams (e.g., or all beams) that can be possibly configured for backhaullink communications with the different upstream node (e.g., a receivebeam or transmit beam).

In another example, in determining to establish the first backhaulconnection at Block 304, optionally at Block 310, an indication of thefirst upstream node and/or the first transmit/receive beam pair can bereceived from a configuration node. In an aspect, beam determiningcomponent 256, e.g., in conjunction with processor(s) 212, memory 216,transceiver 202, backhaul component 242, etc., can receive theindication of the first upstream node and/or the first transmit/receivebeam pair from the configuration node. For example, the configurationnode may include a node of a wireless network that may be part of a EPC160, 5GC 190, or other centralized entity that can communicate withvarious nodes (e.g., various JAB nodes, which may include one or morebase stations 102, etc.). In an example, beam determining component 256can receive the indication based on providing results of beam training(e.g., in one or more beam reports) to the configuration node orotherwise. In one example, the configuration node can select, for thebase station 102, the first upstream node and/or the transmit/receivebeam pair to use in communicating therewith, and may do so for otherbase stations as well.

In method 300, at Block 312, it can be determined to establish a secondbackhaul connection with a second upstream node for access linkcommunications with a second downstream node. In an aspect, beamdetermining component 256, e.g., in conjunction with processor(s) 212,memory 216, transceiver 202, backhaul component 242, etc., can determineto establish the second backhaul connection with the second upstreamnode for access link communications with the second downstream node. Forexample, beam determining component 256 can determine to establish thesecond connection based at least in part on establishing the access linkconnection with the second downstream node. In this example, beamdetermining component 256 can determine the second upstream node to usefor transmitting uplink communications received from the seconddownstream node (or one or more other downstream nodes connected to thesecond downstream node).

In one example, beam determining component 256 can determine toestablish the second backhaul connection with the second upstream nodebased on a signal quality or strength (e.g., signal-to-noise ratio(SNR), signal-to-interference-and-noise ratio (SINR), received signalstrength indicator (RSSI), reference signal received power (RSRP),reference signal received quality (RSRQ), etc.) or other property ofsignals received from the second upstream node. For example, beamdetermining component 256 can measure signals received from variousupstream nodes and can compare a signal strength or quality of thesignals to determine the second upstream node with which to establishthe second backhaul connection. This may include comparing beamsreceived from the various upstream nodes, as described above. Moreover,beam determining component 256 may determine, in the presence ofclutter, to select the second upstream node used for communications ofthe second downstream node to be different from the first upstream nodeused for communications of the first downstream node.

FIG. 4 illustrates an example of a base station 402 establishingconnections with different upstream nodes 404, 406 for serving differentdownstream nodes 408, 410. In FIG. 4, Node A 402 (which can be a basestation IAB node) can communicate with multiple upstream nodes,including Node B 404 and Node C 406, which can also be base station IABnodes, to serve multiple downstream nodes including UE 1 408 and UE 2410. In this example, Node A 402 can serve as a FD IAB node sending DLdata to UE 1 408 via reflector/building. If Node A establishes a DLconnection from Node B 404 to Node A 402, car/clutter in the connectionbetween Node A 402 and UE 1 408 connection can cause self-interference(which can lead to reduction in SINR of the backhaul connection betweenNode B 404 and Node A 402). To mitigate this condition, Node A 402 canestablish a DL with a different upstream node, such as Node C 406, forcommunications related to the UE 1 408. Similarly, Node A 402 serving UE2 410 can use Node C 406 or Node B 404 (or another node) as an upstreamnode for either DL or UL (or both). An UL connection from UE 2 410 toNode B 404 (via Node A 402) is shown in dashed lines for the connection.In any case, the choice of upstream node to Node A 402 can be UEspecific, such that for a given UE (or other downstream node served byNode A 402), the selected upstream node can handle DL and ULcommunications for the UE (or other downstream node). In anotherexample, the choice of upstream node to Node A 402 can be specific to DLor UL for a given UE, such that for a given UE (or other downstreamnode), Node A 402 can use different upstream nodes to which to transmituplink communications from the UE and from which to receive downstreamcommunications for the UE. Moreover, for example, choice oftransmit/receive beam(s) can similarly be UE specific and/or specific toDL or UL for a given UE.

FIG. 4 may illustrate the impact of clutter on the communications, and abeam determining component 256 of the base station 402 can determinewhich upstream nodes to connect with and/or which transmit/receive beamsto use based on beam training, as described. In this example, the beamtraining may expose interference caused by the clutter based ondetermining that connections with certain upstream nodes using certaintransmit/receive beams for a given downstream node (or relatedtransmit/receive beam pair) can cause interference (e.g., SINR, SNR,etc.) that achieves a threshold at the base station 102. Beamdetermining component 256 can refrain from establishing connection withupstream nodes, and/or can determine different upstream nodes with whichto establish a connection instead, where it determines that at least athreshold level of interference or self-interference to the base station102 results when the base station 102 is transmitting to the downstreamnode while receiving from the upstream node, and/or vice versa (e.g., asdetermined during beam training). In one example, beam determiningcomponent 256 can determine to refrain from establishing connection withupstream nodes based on comparing corresponding signal strength orquality measurements associated with the upstream nodes and/or one ormore beams to a threshold. In another example, beam determiningcomponent 256 can determine to refrain from establishing connection withupstream nodes based on comparing corresponding signal strength orquality measurements associated with the upstream nodes and/orcorresponding one or more beams to signal strength or qualitymeasurements associated with the other upstream nodes and/orcorresponding one or more beams.

In an example, in determining to establish the second backhaulconnection at Block 312, optionally at Block 314, the secondtransmit/receive beam pair can be determined based on the beam training.In an aspect, beam determining component 256, e.g., in conjunction withprocessor(s) 212, memory 216, transceiver 202, backhaul component 242,etc., can determine the second upstream node and/or the secondtransmit/receive beam pair based on the beam training. As described, forexample, this may include beam determining component 256 firstdetermining to establish the second connection with the second upstreamnode based at least in part on signal properties of signals receivedfrom the second upstream node. In addition, this can include beamdetermining component 256 determining the second transmit/receive beampair to use with the second upstream node based on an indication of abeam pair received from the second upstream node, determining desirablebeam pairs that are not subject to self-interference from clutter (e.g.,based on SINR, SNR, or other signal measurements, etc.) and selecting orotherwise requesting to use such beam pairs, etc.

In one example, beam determining component 256 can determine the secondupstream node based on determining that, for a different upstream node(e.g., the first upstream node), access link communications with thesecond downstream node cause self-interference to backhaul linkcommunications from the different upstream node. For example, beamdetermining component 256 can discover the self-interference during beamtraining, such as based on determining a beam configured to be used inthe access link communications (e.g., a transmit beam or receive beam)causes self-interference to one or more beams (e.g., or all beams) thatcan be possibly configured for backhaul link communications with thedifferent upstream node (e.g., a receive beam or transmit beam).

In another example, in determining to establish the second backhaulconnection at Block 304, optionally at Block 316, an indication of thesecond upstream node and/or the second transmit/receive beam pair can bereceived from a configuration node. In an aspect, beam determiningcomponent 256, e.g., in conjunction with processor(s) 212, memory 216,transceiver 202, backhaul component 242, etc., can receive theindication of the second upstream node and/or the secondtransmit/receive beam pair from the configuration node. For example, theconfiguration node may include a node of a wireless network that may bepart of a EPC 160, 5GC 190, or other centralized entity that cancommunicate with various nodes (e.g., various IAB nodes, which mayinclude one or more base stations 102, etc.). In an example, beamdetermining component 256 can receive the indication based on providingresults of beam training (e.g., in one or more beam reports) to theconfiguration node or otherwise. In one example, the configuration nodecan select, for the base station 102, the second upstream node and/orthe second transmit/receive beam pair to use in communicating therewith,and may do so for other base stations as well.

In any case, for example, determination of upstream nodes can be made bya base station 102 (e.g., Node A 402) via beam training to other nodesin the vicinity of itself. Alternately, upstream nodes can be determinedby a central processing node/entity that schedules beam training,collects beam training measurement reports (also referred to herein asbeam reports) and determines upstream nodes (and/or corresponding DL andUL connections) at one or more (e.g., all, or a set of multiple) nodesin the network. In an example, as described, base station 102 canperform beam training to all its neighbor nodes (including UEs andIAB/BS nodes) to determine Rx beams with certain nodes that suffer fromself-interference due to local clutter in environment. Rx beams and/orthe certain nodes that suffer from a threshold amount ofinterference/self-interference can be avoided. In addition, for example,the base station 102 can determine correct and/or viable beam pairs touse for each UE (e.g., or other downstream node) and the correct and/orviable IAB/BS node (e.g., or other upstream node) to connect to for thatUE for DL and UL. As described, for example, beam determining component256, backhaul component 252, or another component of the base station102 can determine the beam pairs or upstream nodes to be avoided basedon received signal strength or quality measurements being below athreshold and/or can determine the viable beam pairs or upstream nodesbased on received signal strength or quality measurements achieving athreshold. Thus, for example, beam determining component 256 candetermine to establish the first backhaul connection and/or candetermine to establish the second backhaul connection based on at leastone of comparing a first signal strength or quality measurement of thefirst beam to a first threshold, and/or comparing a second signalstrength or quality measurement of the second beam to a second threshold

In method 300, at Block 318, the first backhaul connection can beestablished with the first upstream node based on a firsttransmit/receive beam pair. In an aspect, backhaul component 242, e.g.,in conjunction with processor(s) 212, memory 216, transceiver 202, etc.,can establish the first backhaul connection with the first upstream nodebased on the first transmit/receive beam pair. In one example, this caninclude beamforming component 252 beamforming antenna resources totransmit to the first upstream node based on the first transmit/receivebeam pair, beamforming antenna resources to receive signals from thefirst upstream node based on the first transmit/receive beam pair, etc.In addition, for example, backhaul component 242 can establish thebackhaul link connections using a UE function or functionality (UE-F) ofthe IAB node, which can establish a backhaul link connection usingsimilar functions as a UE 104 (e.g., based on performing a random accessprocedure based on discovering the upstream node(s), etc.). For example,the functions for establishing the backhaul link connection can bedefined in a radio access technology (RAT) used by the IAB node and/orUEs 104 for communicating with one or more base stations 102, such as 5GNR.

In method 300, at Block 320, the second backhaul connection can beestablished with the second upstream node based on a secondtransmit/receive beam pair and concurrently with the first connection.In an aspect, backhaul component 242, e.g., in conjunction withprocessor(s) 212, memory 216, transceiver 202, etc., can establish thesecond backhaul connection with the second upstream node based on thefirst transmit/receive beam pair and concurrently (e.g., simultaneously)with the first connection, or otherwise while the first backhaulconnection is also established with the first upstream node. Moreover,for example, backhaul component 242 can establish the backhaul linkconnection with the second upstream node using a UE function orfunctionality (UE-F) of the IAB node. In addition, for example, backhaulcomponent 242 can communicate with both the first upstream node and thesecond upstream node for communications related respectively todifferent downstream nodes. In one example, this can include beamformingcomponent 252 beamforming antenna resources to transmit to the secondupstream node based on the second transmit/receive beam pair,beamforming antenna resources to receive signals from the secondupstream node based on the second transmit/receive beam pair, etc.,which may be in a different direction from signals beamformed for thefirst upstream node and/or the first downstream node.

FIG. 5 is a block diagram of a MIMO communication system 500 includingbase stations 102-a and 102-b that can communicate over a wirelessbackhaul, in accordance with various aspects of the present disclosure.The MIMO communication system 500 may illustrate aspects of the wirelesscommunication access network 100 described with reference to FIG. 1. Thebase stations 102-a, 102-b may be an example of aspects of the basestation 102 described with reference to FIG. 1. The base station 102-amay be equipped with antennas 534 and 535, and the base station 102-bmay be equipped with antennas 552 and 553. In the MIMO communicationsystem 500, the base station 102-a may be able to send data overmultiple communication links at the same time. Each communication linkmay be called a “layer” and the “rank” of the communication link mayindicate the number of layers used for communication. For example, in a2×2 MIMO communication system where base station 102-a transmits two“layers,” the rank of the backhaul link between the base station 102-aand the base station 102-b is two.

At the base station 102-a, a transmit (Tx) processor 520 may receivedata from a data source. The transmit processor 520 may process thedata. The transmit processor 520 may also generate control symbols orreference symbols. A transmit MIMO processor 530 may perform spatialprocessing (e.g., precoding) on data symbols, control symbols, orreference symbols, if applicable, and may provide output symbol streamsto the transmit modulator/demodulators 532 and 533. Eachmodulator/demodulator 532 through 533 may process a respective outputsymbol stream (e.g., for OFDM, etc.) to obtain an output sample stream.Each modulator/demodulator 532 through 533 may further process (e.g.,convert to analog, amplify, filter, and upconvert) the output samplestream to obtain a DL signal. In one example, DL signals frommodulator/demodulators 532 and 533 may be transmitted via the antennas534 and 535, respectively.

The base station 102-b may be an example of aspects of the base station102 (or other upstream nodes) described with reference to FIGS. 1-2. Atthe base station 102-b, the antennas 552 and 553 may receive the DLsignals from the base station 102-a and may provide the received signalsto the modulator/demodulators 554 and 555, respectively. Eachmodulator/demodulator 554 through 555 may condition (e.g., filter,amplify, downconvert, and digitize) a respective received signal toobtain input samples. Each modulator/demodulator 554 through 555 mayfurther process the input samples (e.g., for OFDM, etc.) to obtainreceived symbols. A MIMO detector 556 may obtain received symbols fromthe modulator/demodulators 554 and 555, perform MIMO detection on thereceived symbols, if applicable, and provide detected symbols. A receive(Rx) processor 558 may process (e.g., demodulate, deinterleave, anddecode) the detected symbols, providing decoded data for the UE 104 to adata output, and provide decoded control information to a processor 580,or memory 582.

The processor 580 may in some cases execute stored instructions toinstantiate a backhaul component 242 (see e.g., FIGS. 1 and 2).

On the uplink (UL), at the base station 102-b, a transmit processor 564may receive and process data from a data source. The transmit processor564 may also generate reference symbols for a reference signal. Thesymbols from the transmit processor 564 may be precoded by a transmitMIMO processor 566 if applicable, further processed by themodulator/demodulators 554 and 555 (e.g., for SC-FDMA, etc.), and betransmitted to the base station 102-a in accordance with thecommunication parameters received from the base station 102-a. At thebase station 102-a, the UL signals from the base station 102-b may bereceived by the antennas 534 and 535, processed by themodulator/demodulators 532 and 533, detected by a MIMO detector 536 ifapplicable, and further processed by a receive processor 538. Thereceive processor 538 may provide decoded data to a data output and tothe processor 540 or memory 542.

The processor 540 may in some cases execute stored instructions toinstantiate a backhaul component 242 (see e.g., FIGS. 1 and 2).

The components of the base station 102-b may, individually orcollectively, be implemented with one or more application-specificintegrated circuits (ASICs) adapted to perform some or all of theapplicable functions in hardware. Each of the noted modules may be ameans for performing one or more functions related to operation of theMIMO communication system 500. Similarly, the components of the basestation 102-a may, individually or collectively, be implemented with oneor more ASICs adapted to perform some or all of the applicable functionsin hardware. Each of the noted components may be a means for performingone or more functions related to operation of the MIMO communicationsystem 500.

In addition, the base station 102-a and/or 102-b may communicate withdownstream nodes, which may include one or more UEs 104 or other basestations, using similar mechanisms as described for base station 102-aand base station 102-b, respectively (e.g., where the downstream nodecan use components and functions described above with respect to basestation 102-b, and base station 102-a or base station 102-b as anupstream node can use components and functions described above withrespect to base station 102-a).

The following aspects are illustrative only and aspects thereof may becombined with aspects of other embodiments or teaching described herein,without limitation.

Aspect 1 is a method of wireless communication including determining, bya node, to establish a first backhaul connection with a first upstreamnode for access link communications with a first downstream node,determining, by the node, to establish a second backhaul connection witha second upstream node for access link communications with a seconddownstream node, establishing the first backhaul connection with thefirst upstream node based on a first transmit/receive beam pair, andestablishing the second backhaul connection with the second upstreamnode based on a second transmit/receive beam pair and while the firstbackhaul connection is established with the first upstream node.

In Aspect 2, the method of Aspect 1, includes performing beam trainingand determining that a first beam from the first upstream node isdesirable for access link communications with the first downstream node,wherein determining to establish the first backhaul connection is basedon the beam training and the first beam.

In Aspect 3, the method of Aspect 2 includes determining that a secondbeam from the second upstream node is desirable for access linkcommunications with the second downstream node, wherein determining toestablish the second backhaul connection is based on the beam trainingand the second beam.

In Aspect 4, the method of Aspect 3 includes wherein determining toestablish the first backhaul connection and determining to establish thesecond backhaul connection is based on comparing a first signal qualityof the first beam to a first threshold, and comparing a second signalquality of the second beam to a second threshold.

In Aspect 5, the method of Aspect 4 includes wherein the first signalquality and the second signal quality correspond to at least one of asignal-to-noise ratio (SNR) or a signal-to-interference-and-noise ratio(SINR).

In Aspect 6, the method of any of Aspects 1 to 5 include performing beamtraining and sending one or more beam reports to a centralized entity,wherein determining to establish the first backhaul connection anddetermining to establish the second backhaul connection are based on oneor more commands received from the centralized entity based on the oneor more beam reports.

Aspect 7 is an apparatus for wireless communication including atransceiver, a memory configured to store instructions, and one or moreprocessors communicatively coupled with the transceiver and the memory,wherein the one or more processors are configured to execute theinstructions to perform the operations of one or more methods in any ofAspects 1 to 6.

Aspect 8 is an apparatus for wireless communication, including means forperforming the operations of one or more methods in any of Aspects 1 to6.

Aspect 9 is a computer-readable medium including code executable by oneor more processors to perform the operations of one or more methods inany of Aspects 1 to 6.

The above detailed description set forth above in connection with theappended drawings describes examples and does not represent the onlyexamples that may be implemented or that are within the scope of theclaims. The term “example,” when used in this description, means“serving as an example, instance, or illustration,” and not “preferred”or “advantageous over other examples.” The detailed description includesspecific details for the purpose of providing an understanding of thedescribed techniques. These techniques, however, may be practicedwithout these specific details. In some instances, well-known structuresand apparatuses are shown in block diagram form in order to avoidobscuring the concepts of the described examples.

Information and signals may be represented using any of a variety ofdifferent technologies and techniques. For example, data, instructions,commands, information, signals, bits, symbols, and chips that may bereferenced throughout the above description may be represented byvoltages, currents, electromagnetic waves, magnetic fields or particles,optical fields or particles, computer-executable code or instructionsstored on a computer-readable medium, or any combination thereof.

The various illustrative blocks and components described in connectionwith the disclosure herein may be implemented or performed with aspecially-programmed device, such as but not limited to a processor, adigital signal processor (DSP), an ASIC, a field programmable gate array(FPGA) or other programmable logic device, a discrete gate or transistorlogic, a discrete hardware component, or any combination thereofdesigned to perform the functions described herein. Aspecially-programmed processor may be a microprocessor, but in thealternative, the processor may be any conventional processor,controller, microcontroller, or state machine. A specially-programmedprocessor may also be implemented as a combination of computing devices,e.g., a combination of a DSP and a microprocessor, multiplemicroprocessors, one or more microprocessors in conjunction with a DSPcore, or any other such configuration.

The functions described herein may be implemented in hardware, software,or any combination thereof. If implemented in software executed by aprocessor, the functions may be stored on or transmitted over as one ormore instructions or code on a non-transitory computer-readable medium.Other examples and implementations are within the scope and spirit ofthe disclosure and appended claims. For example, due to the nature ofsoftware, functions described above can be implemented using softwareexecuted by a specially programmed processor, hardware, hardwiring, orcombinations of any of these. Features implementing functions may alsobe physically located at various positions, including being distributedsuch that portions of functions are implemented at different physicallocations. Moreover, the term “or” is intended to mean an inclusive “or”rather than an exclusive “or.” That is, unless specified otherwise, orclear from the context, the phrase, for example, “X employs A or B” isintended to mean any of the natural inclusive permutations. That is, forexample the phrase “X employs A or B” is satisfied by any of thefollowing instances: X employs A; X employs B; or X employs both A andB. Also, as used herein, including in the claims, “or” as used in a listof items prefaced by “at least one of” indicates a disjunctive list suchthat, for example, a list of “at least one of A, B, or C” means A or Bor C or AB or AC or BC or ABC (A and B and C).

Computer-readable media includes both computer storage media andcommunication media including any medium that facilitates transfer of acomputer program from one place to another. A storage medium may be anyavailable medium that can be accessed by a general purpose or specialpurpose computer. By way of example, and not limitation,computer-readable media can comprise RAM, ROM, EEPROM, CD-ROM or otheroptical disk storage, magnetic disk storage or other magnetic storagedevices, or any other medium that can be used to carry or store desiredprogram code means in the form of instructions or data structures andthat can be accessed by a general-purpose or special-purpose computer,or a general-purpose or special-purpose processor. Also, any connectionis properly termed a computer-readable medium. For example, if thesoftware is transmitted from a website, server, or other remote sourceusing a coaxial cable, fiber optic cable, twisted pair, digitalsubscriber line (DSL), or wireless technologies such as infrared, radio,and microwave, then the coaxial cable, fiber optic cable, twisted pair,DSL, or wireless technologies such as infrared, radio, and microwave areincluded in the definition of medium. Disk and disc, as used herein,include compact disc (CD), laser disc, optical disc, digital versatiledisc (DVD), floppy disk and Blu-ray disc where disks usually reproducedata magnetically, while discs reproduce data optically with lasers.Combinations of the above are also included within the scope ofcomputer-readable media.

The previous description of the disclosure is provided to enable aperson skilled in the art to make or use the disclosure. Variousmodifications to the disclosure will be readily apparent to thoseskilled in the art, and the common principles defined herein may beapplied to other variations without departing from the spirit or scopeof the disclosure. Furthermore, although elements of the describedaspects and/or embodiments may be described or claimed in the singular,the plural is contemplated unless limitation to the singular isexplicitly stated. Additionally, all or a portion of any aspect and/orembodiment may be utilized with all or a portion of any other aspectand/or embodiment, unless stated otherwise. Thus, the disclosure is notto be limited to the examples and designs described herein but is to beaccorded the widest scope consistent with the principles and novelfeatures disclosed herein.

What is claimed is:
 1. A method of wireless communication, comprising:determining, by a node, to establish a first backhaul connection with afirst upstream node for access link communications with a firstdownstream node; determining, by the node, to establish a secondbackhaul connection with a second upstream node for access linkcommunications with a second downstream node; establishing the firstbackhaul connection with the first upstream node based on a firsttransmit/receive beam pair where at least a first receive beam of thefirst transmit/receive beam pair is determined to have less than a firstthreshold level of self-interference from access link transmission tothe first downstream node; and establishing, while the first backhaulconnection is established with the first upstream node, the secondbackhaul connection with the second upstream node based on a secondtransmit/receive beam pair where at least a second receive beam of thesecond transmit/receive beam pair is determined to have less than asecond threshold level of self-interference from access linktransmission to the second downstream node.
 2. The method of claim 1,further comprising performing beam training to determine signalmeasurements related to multiple transmit beams and multiple receivebeams, wherein the first receive beam is determined to have less thanthe first threshold level of self-interference based on one or more ofthe signal measurements determined based on the beam training.
 3. Themethod of claim 2, wherein the second receive beam is determined to haveless than the second threshold level of self-interference based on oneor more of the signal measurements determined based on the beamtraining.
 4. The method of claim 2, wherein determining to establish thefirst backhaul connection and determining to establish the secondbackhaul connection is based on comparing a first signal strength orquality measurement of a first signal received over the first receivebeam to a first threshold, and comparing a second signal strength orquality measurement of a second signal received over the second receivebeam to a second threshold.
 5. The method of claim 4, wherein the firstsignal strength or quality measurement and the second signal strength orquality measurement correspond to at least one of a signal-to-noiseratio (SNR) or a signal-to-interference-and-noise ratio (SINK).
 6. Themethod of claim 1, further comprising performing beam training andsending one or more beam reports to a centralized entity, whereindetermining to establish the first backhaul connection and determiningto establish the second backhaul connection are based on one or morecommands received from the centralized entity based on the one or morebeam reports.
 7. The method of claim 1, wherein the node, the firstupstream node, or the second upstream node includes at least one of anintegrated access and backhaul (IAB) node, a user equipment (UE), acustomer premises equipment (CPE), an access point, a relay node, or arepeater.
 8. An apparatus for wireless communication, comprising: atransceiver; a memory configured to store instructions; and one or moreprocessors communicatively coupled with the transceiver and the memory,wherein the one or more processors are configured to: determine toestablish a first backhaul connection with a first upstream node foraccess link communications with a first downstream node; determine toestablish a second backhaul connection with a second upstream node foraccess link communications with a second downstream node; establish thefirst backhaul connection with the first upstream node based on a firsttransmit/receive beam pair where at least a first receive beam of thefirst transmit/receive beam pair is determined to have less than a firstthreshold level of self-interference from access link transmission tothe first downstream node; and establish, while the first backhaulconnection is established with the first upstream node, the secondbackhaul connection with the second upstream node based on a secondtransmit/receive beam pair where at least a second receive beam of thesecond transmit/receive beam pair is determined to have less than asecond threshold level of self-interference from access linktransmission to the second downstream node.
 9. The apparatus of claim 8,wherein the one or more processors are further configured to performbeam training to determine signal measurements related to multipletransmit beams and multiple receive beams, wherein the first receivebeam is determined to have less than the first threshold level ofself-interference based on one or more of the signal measurementsdetermined based on the beam training.
 10. The apparatus of claim 9, thesecond receive beam is determined to have less than the second thresholdlevel of self-interference based on one or more of the signalmeasurements determined based on the beam training.
 11. The apparatus ofclaim 9, wherein the one or more processors are configured to determineto establish the first backhaul connection and determine to establishthe second backhaul connection based on comparing a first signalstrength or quality measurement of a first signal received over thefirst receive beam to a first threshold, and comparing a second signalstrength or quality measurement of a second signal received over thesecond receive beam to a second threshold.
 12. The apparatus of claim11, wherein the first signal strength or quality measurement and thesecond signal strength or quality measurement correspond to at least oneof a signal-to-noise ratio (SNR) or a signal-to-interference-and-noiseratio (SINK).
 13. The apparatus of claim 8, wherein the one or moreprocessors are further configured to perform beam training and send oneor more beam reports to a centralized entity, wherein the one or moreprocessors are configured to determine to establish the first backhaulconnection and determine to establish the second backhaul connectionbased on one or more commands received from the centralized entity basedon the one or more beam reports.
 14. The apparatus of claim 8, whereinthe apparatus, the first upstream node, or the second upstream nodeincludes at least one of an integrated access and backhaul (IAB) node, auser equipment (UE), a customer premises equipment (CPE), an accesspoint, a relay node, or a repeater.
 15. An apparatus for wirelesscommunication, comprising: means for determining to establish a firstbackhaul connection with a first upstream node for access linkcommunications with a first downstream node; means for determining toestablish a second backhaul connection with a second upstream node foraccess link communications with a second downstream node; means forestablishing the first backhaul connection with the first upstream nodebased on a first transmit/receive beam pair where at least a firstreceive beam of the first transmit/receive beam pair is determined tohave less than a first threshold level of self-interference from accesslink transmission to the first downstream node; and means forestablishing, while the first backhaul connection is established withthe first upstream node, the second backhaul connection with the secondupstream node based on a second transmit/receive beam pair where atleast a second receive beam of the second transmit/receive beam pair isdetermined to have less than a second threshold level ofself-interference from access link transmission to the second downstreamnode.
 16. The apparatus of claim 15, further comprising means forperforming beam training to determine signal measurements related tomultiple transmit beams and multiple receive beams, wherein the firstreceive beam is determined to have less than the first threshold levelof self-interference based on one or more of the signal measurementsdetermined based on the beam training.
 17. The apparatus of claim 16,wherein the second receive beam is determined to have less than thesecond threshold level of self-interference based on one or more of thesignal measurements determined based on the beam training.
 18. Theapparatus of claim 16, wherein the means for determining to establishthe first backhaul connection and determining to establish the secondbackhaul connection is based on comparing a first signal strength orquality measurement of a first signal received over the first receivebeam to a first threshold, and comparing a second signal strength orquality measurement of a second signal received over the second receivebeam to a second threshold.
 19. The apparatus of claim 18, wherein thefirst signal strength or quality measurement and the second signalstrength or quality measurement correspond to at least one of asignal-to-noise ratio (SNR) or a signal-to-interference-and-noise ratio(SINK).
 20. The apparatus of claim 15, further comprising means forperforming beam training and sending one or more beam reports to acentralized entity, wherein the means for determining to establish thefirst backhaul connection determines to establish the first backhaulconnection based on one or more commands received from the centralizedentity based on the one or more beam reports, and wherein the means fordetermining to establish the second backhaul connection determines toestablish the second backhaul connection based on one or more commandsreceived from the centralized entity based on the one or more beamreports.
 21. The apparatus of claim 15, wherein the apparatus, the firstupstream node, or the second upstream node includes at least one of anintegrated access and backhaul (IAB) node, a user equipment (UE), acustomer premises equipment (CPE), an access point, a relay node, or arepeater.
 22. A non-transitory computer-readable medium, comprising codeexecutable by one or more processors to perform wireless communications,the code comprising code for: determining, by a node, to establish afirst backhaul connection with a first upstream node for access linkcommunications with a first downstream node; determining, by the node,to establish a second backhaul connection with a second upstream nodefor access link communications with a second downstream node;establishing the first backhaul connection with the first upstream nodebased on a first transmit/receive beam pair where at least a firstreceive beam of the first transmit/receive beam pair is determined tohave less than a first threshold level of self-interference from accesslink transmission to the first downstream node; and establishing, whilethe first backhaul connection is established with the first upstreamnode, the second backhaul connection with the second upstream node basedon a second transmit/receive beam pair where at least a second receivebeam of the second transmit/receive beam pair is determined to have lessthan a second threshold level of self-interference from access linktransmission to the second downstream node.
 23. The non-transitorycomputer-readable medium of claim 22, further comprising code forperforming beam training to determine signal measurements related tomultiple transmit beams and multiple receive beams, wherein the firstreceive beam is determined to have less than the first threshold levelof self-interference based on one or more of the signal measurementsdetermined based on the beam training.
 24. The non-transitorycomputer-readable medium of claim 23, wherein the second receive beam isdetermined to have less than the second threshold level ofself-interference based on one or more of the signal measurementsdetermined based on the beam training.
 25. The non-transitorycomputer-readable medium of claim 23, wherein the code for determiningto establish the first backhaul connection and determining to establishthe second backhaul connection is based on comparing a first signalstrength or quality measurement of a first signal received over thefirst receive beam to a first threshold, and comparing a second signalstrength or quality measurement of a second signal received over thesecond receive beam to a second threshold.
 26. The non-transitorycomputer-readable medium of claim 25, wherein the first signal strengthor quality measurement and the second signal strength or qualitymeasurement correspond to at least one of a signal-to-noise ratio (SNR)or a signal-to-interference-and-noise ratio (SINR).
 27. Thenon-transitory computer-readable medium of claim 22, further comprisingcode for performing beam training and sending one or more beam reportsto a centralized entity, wherein the code for determining to establishthe first backhaul connection determines to establish the first backhaulconnection based on one or more commands received from the centralizedentity based on the one or more beam reports, and wherein the code fordetermining to establish the second backhaul connection determines toestablish the second backhaul connection based on one or more commandsreceived from the centralized entity based on the one or more beamreports.
 28. The non-transitory computer-readable medium of claim 22,wherein the node, the first upstream node, or the second upstream nodeincludes at least one of an integrated access and backhaul (IAB) node, auser equipment (UE), a customer premises equipment (CPE), an accesspoint, a relay node, or a repeater.